Periodex

General properties

Group

group 18 (noble gases)

Period

period 6

Category

noble gases

Standard atomic weight

-

Melting point

202 K (-71 °C)

Boiling point

211.5 K (-61.6 °C)

Phase at STP

gas

Additional properties

Block

p-block

Electron configuration

[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁶

Electrons per shell

2, 8, 18, 32, 18, 8

Electronegativity

2.2

Density

9.73 g/L

Oxidation states

0, +2, +6

CAS Number

10043-92-2

Natural isotopes

Discovery history

Discovered by

Ernest Rutherford आणि Robert B. Owens

Year of discovery

1899

Origin of name

From radium, as it was first detected as an emission from radium during radioactive decay